Breast carcinoma is one of the major causes of death in women, affecting about 1 in 10 North American women. It has been shown, however, that the risk of mortality from breast cancer can be reduced with early detection. Mammography is the most sensitive technique currently available for the detection of minimal breast cancer and film-screen imaging is the most common mammographic technique used today. The goal of the Phase I-Phase II project is to perform research on a low energy, high resolution x-ray sensor utilizing a charge-coupled device (CCD) coupled to a scintillating micro-fiber (SMF) plate of CsI. Using the novel scintillation plate as an x-ray detector/converter should reduce patient dose while improving image quality. The long-term objectives are to produce a low-dose digital mammographic CCD-SMF imager with high spatial resolution, high detective quantum efficiency (DQE(f)), and low patient scatter acceptance based on existing designs. Phase I will consist of designing and constructing a small field-of-view imaging sensor with the associated electronics readout necessary for acquiring static images. The characteristics of the sensor system will be evaluated. The research and development will be carried out in collaboration with scientists at Brigham and Woman's Hospital.